/*
 * Copyright (C) 2011-2019 Intel Corporation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <sl_uswitchless.h>
#include <sl_atomic.h>
#include <sl_workers.h>
#include <sgx_error.h>
#include <sl_debug.h>


/* sgx_ecall_switchless() from uRTS calls this function to do the real job */
sgx_status_t sl_uswitchless_do_switchless_ecall(struct sl_uswitchless* handle,
                                          const unsigned int ecall_id,
                                          void* ecall_ms,
                                          int* need_fallback)
{
    struct sl_fcall_buf buf;
    int error = 0;

    /* If no trusted workers are running, then fallback */
    if (handle->us_tworkers.num_running == 0) 
        goto on_fallback;

    
    if (handle->us_tworkers.num_sleeping > 0)
    {
        wake_all_threads(&handle->us_tworkers);
    }


    buf.fbf_status = SL_FCALL_STATUS_INIT;
    buf.fbf_ret = SGX_ERROR_UNEXPECTED;
    buf.fbf_fn_id = ecall_id;
    buf.fbf_ms_ptr = ecall_ms;

    error = sl_fcall_mngr_call(&handle->us_fecall_mngr, &buf, handle->us_config.retries_before_fallback);
    if (error) 
        goto on_fallback;

    *need_fallback = 0;
    lock_inc64(&handle->us_tworkers.stats.processed);
    return buf.fbf_ret;
on_fallback:
    *need_fallback = 1;
    lock_inc64(&handle->us_tworkers.stats.missed);
    sl_workers_notify_event(&handle->us_tworkers, SL_WORKER_EVENT_MISS);
    return SGX_ERROR_BUSY;
}


